Plenty of sunshine, daytime temperatures in the 80s and no rain — all have Napa Valley wine grape grower Jon Ruel in a buoyant mood about prospects for this fall’s harvest.
He’s director of viticulture and winemaking for Trefethen Family Vineyards in the Oak Knoll District and president of Napa Valley Grapegrowers.
Located in the southern end of the valley near San Pablo Bay, the cooler, more moderate climate of the district is well-suited to Trefethen’s nine varietals: Chardonnay, Cabernet Sauvignon, Merlot, Riesling, Pinot Noir, Cabernet Franc, Malbec, Petit Verdot, and Viognier.
“I’m really excited by our Chardonnay,” he says. “It looks like a return to normal yields; last year, this variety was down about 30 percent.”
Veraison has progressed in his Cabernet Sauvignon blocks, which started to turn color in late July. That’s about normal and several weeks earlier than the past two seasons, Ruel says.
Sunny weather during bloom favored good fertilization and fruit set, resulting in a respectable cluster size. “Across the board, yields look very good at this point,” he says.
Ruel expects this year’s harvest to get under way soon, when the Pinot Noir reaches 20 Brix for sparkling wine. The Chardonnay will follow, probably not long after Labor Day. Ahead of harvest, crews thinned clusters to balance fruit and foliage to achieve the desired quality for each variety.
“Our Merlot appears to have been a little too ambitious in producing a crop this year,” Ruel says. “So, in some, cases, we’ve been dropping as much as half the fruit. Our Chardonnay and Cabernet Sauvignon were already in pretty good balance. We’ve just been touching them up, dropping some clusters here and there.”
Earlier this year he was dealing with some rapid growth in parts of his vineyards. “Bud break wasn’t particularly early, but we had some very vigorous shoot growth. We had to sucker our weaker blocks first to divert energy to the shoots we wanted to keep. And we had to leave some extra shoots in the vigorously-growing blocks so they would use up the extra vigor a few weeks later.”
Ruel treated vines with wettable sulfur to control powdery mildew until bloom, before switching to a combination of organic and synthetic fungicides. To reduce buildup of resistance by disease pathogens, he rotates sprays among different classes and types of products. However, he reduced the interval between sprays from the normal 21-days to 14 days for better control under the high disease pressure.
Trefethen Vineyards is one of many in Napa and other counties within a quarantine area as part of program designed to wipe out the invasive European grapevine moth. No moths have been found in his vines.
“Controlling spread of this pest in the Napa Valley has been a real success for growers,” says Ruel. “Since it was first discovered in the valley several years ago, the numbers of moths have really declined as we continue trapping and spraying in a countywide coordinated program to eradicate the insect.”